Ten free cardiac NCLEX practice questions with full rationales — ACS and MI priorities, heart failure, atrial fibrillation, lethal dysrhythmias, nitroglycerin, and beta-blockers. Answer each one, then reveal the correct answer and see why every option is right or wrong. No sign-up needed to practice here.
High-Yield Cardiac Review
Cardiovascular content is one of the most heavily tested areas on the NCLEX because a missed cardiac cue can be fatal. In acute coronary syndrome (ACS), think "time is muscle." The current AHA/ACC priority is rapid recognition and a 12-lead ECG within 10 minutes of arrival to identify a STEMI, followed by chewable aspirin (unless contraindicated), and nitroglycerin if the client is not hypotensive and has not taken a PDE5 inhibitor. Supplemental oxygen is no longer given to everyone — apply it only when SpO2 falls below 90% or the client is dyspneic/hypoxic. Routine "morphine first" is out; morphine is reserved for pain unrelieved by nitrates. Nitroglycerin is held for a systolic BP under 90 mm Hg and is absolutely contraindicated within about 24 hours of sildenafil and 48 hours of tadalafil because the combination causes life-threatening hypotension.
Heart failure questions hinge on left-versus-right. Left-sided failure backs up into the Lungs (crackles, dyspnea, orthopnea, paroxysmal nocturnal dyspnea). Right-sided failure backs up into the Rest of the body (JVD, dependent/peripheral edema, hepatomegaly, ascites). Core self-management teaching: weigh every morning after voiding on the same scale, and report a gain of 2-3 lb in a day or about 5 lb in a week, follow a low-sodium diet, take medications consistently, and report worsening dyspnea or edema.
Dysrhythmias split into shockable and non-shockable. Ventricular fibrillation and pulseless ventricular tachycardia are shockable — the priority is immediate defibrillation plus high-quality CPR. Asystole and PEA are non-shockable — CPR plus epinephrine, never defibrillation. Atrial fibrillation is irregularly irregular and causes atrial stasis, so stroke prevention with anticoagulation is the leading concern alongside rate/rhythm control. Know the key drugs: antiplatelet aspirin, vasodilating nitroglycerin, and beta-blockers such as metoprolol — check the apical pulse and hold for HR under 60 or a low SBP, and never stop them abruptly.
Cardiac NCLEX Practice Questions
Question 1 · Acute coronary syndrome / MI priority
A client arrives at the emergency department reporting crushing substernal chest pressure that began 30 minutes ago, radiating to the left arm, with diaphoresis and nausea. Which action should the nurse take first?
- A Obtain a 12-lead ECG
- B Draw a serum troponin level
- C Administer sublingual nitroglycerin
- D Apply a non-rebreather oxygen mask at 15 L/min
Show answer & rationale
Correct answer: A
Current AHA/ACC ACS guidelines direct that a 12-lead ECG be obtained and interpreted within 10 minutes of arrival for any client with suspected cardiac chest pain. The ECG is the single test that distinguishes a STEMI (which needs emergent reperfusion in the cath lab) from other presentations, and it drives every downstream decision. 'Time is muscle' — the faster the STEMI is identified, the more myocardium is salvaged. Obtaining the ECG is a rapid, noninvasive assessment, and assessment/diagnostics that determine emergent treatment come first. Administering sublingual nitroglycerin is an important early intervention, but it is not the first step: the nurse must first confirm the client is not hypotensive (hold for SBP below 90 mm Hg) and has not taken a PDE5 inhibitor, and giving it before the ECG could delay STEMI recognition. Drawing a troponin (normal is roughly less than 0.04 ng/mL for conventional assays) is part of the diagnostic workup, but troponin rises over hours — a normal early value does not rule out MI, so waiting on it or prioritizing it would delay care. A non-rebreather at 15 L/min is inappropriate routine care: current guidance withholds supplemental oxygen unless SpO2 is below 90% or the client is dyspneic/hypoxic, because hyperoxia can worsen coronary vasoconstriction. Clinical pearl: the modern ACS sequence is ECG first, aspirin, then nitroglycerin (if not hypotensive and no PDE5 inhibitor) and oxygen only if hypoxic — MONA is outdated.
Question 2 · Oxygen in acute MI
A client with suspected acute myocardial infarction has an SpO2 of 95% on room air and denies shortness of breath. A newly oriented nurse reaches for a nasal cannula. Based on current AHA guidance, the experienced nurse should advise the new nurse to:
- A Wait to give oxygen until the troponin confirms an MI
- B Apply a non-rebreather mask at 15 L/min to maximize oxygen delivery
- C Withhold supplemental oxygen and continue to monitor the SpO2
- D Apply oxygen at 2 L/min to every client with chest pain
Show answer & rationale
Correct answer: C
Current AHA/ACC recommendations no longer support routine oxygen for all clients with chest pain. Supplemental oxygen is indicated only when the SpO2 is below 90% or the client is dyspneic or shows signs of hypoxemia. This client's SpO2 of 95% is adequate (a normal SpO2 is 95-100%), so oxygen should be withheld and monitoring continued. Evidence (e.g., the AVOID and DETO2X trials) showed that giving oxygen to normoxic MI clients provides no benefit and may cause hyperoxia-induced coronary vasoconstriction and potential harm. Applying oxygen at 2 L/min to 'every client with chest pain' reflects the outdated MONA approach and ignores the SpO2 threshold. A non-rebreather at 15 L/min would deliver a very high FiO2 to a client who is not hypoxic, exposing them to the risks of hyperoxia with no benefit. Waiting for troponin before deciding about oxygen confuses two separate issues: oxygen is titrated to the SpO2 in real time, not to a lab result, and troponin can take hours to rise. Clinical pearl: 'Oxygen is a drug — dose it to the number.' Give O2 for SpO2 below 90% (or symptomatic hypoxia/respiratory distress), and target normoxia rather than supranormal saturations.
Question 3 · Nitroglycerin — PDE5 contraindication
A client in the emergency department with chest pain mentions taking sildenafil about 4 hours ago for erectile dysfunction. The provider orders sublingual nitroglycerin. What is the nurse's priority action?
- A Give the nitroglycerin only if the client is lying flat
- B Hold the nitroglycerin and notify the provider
- C Double the nitroglycerin dose because sildenafil reduces its effect
- D Administer the nitroglycerin exactly as ordered
Show answer & rationale
Correct answer: B
Nitrates are absolutely contraindicated within 24 hours of sildenafil and within 48 hours of tadalafil. Both nitroglycerin and PDE5 inhibitors are vasodilators; combined, they cause profound, refractory hypotension that can precipitate cardiovascular collapse and death. The nurse must hold the medication and notify the provider so an alternative can be chosen — administering it would be dangerous even though it is 'ordered,' and the nurse is responsible for recognizing this contraindication. Giving it with the client lying flat does not neutralize the drug interaction; positioning does not make a contraindicated nitrate safe. Doubling the dose is dangerously wrong — sildenafil potentiates, not blunts, nitrate-induced vasodilation, so more nitrate would deepen the hypotension. Clinical pearl: always ask about erectile dysfunction and pulmonary hypertension medications before giving any nitrate. Remember the time windows — sildenafil (Viagra) and vardenafil roughly 24 hours; tadalafil (Cialis) up to 48 hours because of its longer half-life. Also recall the standard hold parameter for nitroglycerin: withhold if systolic BP is below 90 mm Hg. Expected, non-dangerous nitrate effects include headache, transient hypotension, and flushing.
Question 4 · Nitroglycerin — client teaching
The nurse teaches a client newly prescribed sublingual nitroglycerin for stable angina. Which statements by the client indicate correct understanding? Select all that apply.
- A A headache or flushing after taking a tablet means the medicine is harming me and I should stop it for good.
- B I'll sit or lie down before taking it because it can make me dizzy.
- C I'll place one tablet under my tongue when I get chest pain, and I can take up to 3 tablets, 5 minutes apart.
- D I can keep taking my sildenafil as usual as long as I space it a few hours from the nitroglycerin.
- E I'll keep the tablets in their original dark glass bottle, tightly capped, not loose in a plastic pill organizer.
- F If my chest pain isn't relieved or is getting worse 5 minutes after the first tablet, I'll call 911, and I can keep taking doses up to 3 total while I wait for help.
Show answer & rationale
Correct answer: B, C, E, F
Correct teaching: at the onset of chest pain, place one tablet under the tongue and repeat every 5 minutes up to 3 tablets total. Under current AHA guidance the two dosing statements are complementary, not contradictory — if pain is unrelieved or worsening 5 minutes after the FIRST dose, activate EMS immediately (unrelieved pain may signal MI), and additional doses (to a maximum of 3) may be taken while awaiting help. Sitting or lying down first is correct because nitroglycerin causes venous/arterial vasodilation and orthostatic hypotension, producing dizziness and fall risk. Storing tablets in the original tightly capped dark glass bottle is correct: nitroglycerin degrades with light, heat, moisture, and air, so plastic organizers reduce potency. Believing headache or flushing means the drug is harmful and must be permanently stopped is wrong — headache, flushing, and mild hypotension are expected, dose-related vasodilatory effects managed with acetaminophen, not reasons to discontinue an effective prescribed drug. Continuing sildenafil is dangerous and wrong: PDE5 inhibitors are contraindicated with nitrates (wait at least 24 hours after sildenafil/vardenafil, 48 hours after tadalafil) because combined vasodilation causes severe, potentially fatal hypotension; merely "spacing them a few hours" does not make it safe. Clinical pearl: a burning or tingling sensation is NOT a reliable indicator of potency — per FDA labeling, potent tablets may produce no tingling, so absence of tingling does not mean the tablet is ineffective. Instead teach proper storage and routine replacement (by the labeled expiration date). Reinforce carrying the medication at all times and calling 911 early rather than delaying.
Question 5 · Heart failure — left vs right sided
The nurse is assessing a client with left-sided heart failure. Which cluster of findings is most consistent with this diagnosis?
- A Hepatomegaly and abdominal ascites
- B Weight loss and dry mucous membranes
- C Jugular venous distention and pitting peripheral edema
- D Bibasilar crackles, dyspnea, and orthopnea
Show answer & rationale
Correct answer: D
Left-sided heart failure causes blood to back up into the pulmonary circulation, producing pulmonary congestion: bibasilar crackles, dyspnea, orthopnea, paroxysmal nocturnal dyspnea, and sometimes a frothy or pink-tinged cough. The memory aid is Left = Lungs. Jugular venous distention and pitting peripheral edema are hallmark signs of right-sided failure, where blood backs up into the systemic venous circulation (Right = Rest of the body). Hepatomegaly and ascites are also right-sided findings, caused by systemic venous congestion of the liver and abdomen. Weight loss and dry mucous membranes suggest a fluid-volume deficit — the opposite of heart failure, which typically causes fluid retention and weight gain. Clinical pearl: left and right failure often coexist because left-sided failure is the most common cause of right-sided failure (the failing left ventricle raises pulmonary pressures, straining the right ventricle). When you see crackles and 'can't breathe lying flat,' think left; when you see JVD, ankle edema, and a congested liver, think right. Monitoring daily weights is the most reliable indicator of fluid status in either type — a sudden gain reflects retained fluid before edema is even visible.
Question 6 · Heart failure — self-management teaching
The nurse provides discharge teaching to a client with chronic heart failure. Which instructions should the nurse include? Select all that apply.
- A "Weigh yourself every morning after you urinate, wearing similar clothing, on the same scale."
- B "Increase your fluid intake to several liters a day to stay well hydrated."
- C "Call your provider if you gain 2 to 3 pounds in a day or about 5 pounds in a week."
- D "Follow a low-sodium diet and avoid adding table salt to your food."
- E "It is fine to skip your medications on days when you feel well."
- F "Report increasing shortness of breath, ankle swelling, or waking up breathless at night."
Show answer & rationale
Correct answer: A, C, D, F
Daily morning weights are the cornerstone of heart-failure self-monitoring because weight change reflects fluid retention before edema or dyspnea appear. The client should weigh at the same time (after voiding, before breakfast), in similar clothing, on the same scale for accuracy. Reporting a gain of 2-3 pounds in a day or about 5 pounds in a week is the standard threshold that signals fluid overload and the need to contact the provider for possible diuretic adjustment. A low-sodium diet is essential because sodium drives water retention and worsens congestion; clients should avoid the salt shaker and processed/canned foods. Reporting worsening dyspnea, new or increasing ankle edema, or paroxysmal nocturnal dyspnea allows early intervention before decompensation. Skipping medications on 'good' days is incorrect and dangerous — heart-failure medications (ACE inhibitors/ARBs, beta-blockers, diuretics) control a chronic condition and abrupt discontinuation can trigger rapid decompensation; beta-blockers in particular must never be stopped abruptly. Increasing fluids to several liters a day is incorrect; many heart-failure clients are placed on a fluid restriction, and increasing intake would worsen volume overload. Clinical pearl: teach clients the phrase 'same time, same scale, same clothes' for weights, and to keep a simple log to bring to appointments.
Question 7 · Atrial fibrillation — priority risk
A client is admitted with new-onset atrial fibrillation and a ventricular rate of 120 beats per minute. The rhythm is described as irregularly irregular. Which is the nurse's priority concern?
- A Risk for respiratory alkalosis
- B Risk for thromboembolic stroke
- C Risk for severe hypoglycemia
- D Risk for symptomatic hypercalcemia
Show answer & rationale
Correct answer: B
In atrial fibrillation the atria quiver rather than contract in a coordinated way, producing the classic irregularly irregular rhythm. Because the atria do not empty effectively, blood stagnates — especially in the left atrial appendage — and forms clots that can embolize to the brain, causing stroke. Preventing thromboembolism with anticoagulation (guided by tools such as the CHA2DS2-VASc score) is therefore the leading priority, alongside controlling the ventricular rate and, when appropriate, the rhythm. Hypoglycemia is unrelated to atrial fibrillation; it involves glucose regulation, not cardiac electrical activity. Respiratory alkalosis is an acid-base disturbance driven by hyperventilation and has no direct causal link to atrial fibrillation. Hypercalcemia is an electrolyte abnormality that can affect cardiac conduction but is not the priority concern created by atrial fibrillation itself; if anything, atrial fibrillation is more classically associated with other triggers such as hyperthyroidism, hypertension, and valve disease. Clinical pearl: 'A-fib clots' — the two big management goals are rate/rhythm control and stroke prevention through anticoagulation. Also remember that when cardioversion is planned in new-onset A-fib present longer than 48 hours, anticoagulation status must be addressed first because cardioverting an unanticoagulated client can dislodge an existing atrial clot.
Question 8 · Lethal dysrhythmia — ventricular fibrillation
A monitored client on the telemetry unit suddenly becomes unresponsive. The cardiac monitor shows ventricular fibrillation. After confirming the client is pulseless and calling for help, which action is the priority?
- A Administer IV amiodarone before any other intervention
- B Prepare the client for synchronized cardioversion
- C Administer atropine 1 mg IV push
- D Defibrillate immediately and resume high-quality CPR
Show answer & rationale
Correct answer: D
Ventricular fibrillation and pulseless ventricular tachycardia are the 'shockable' cardiac arrest rhythms. Per ACLS, the priority is immediate defibrillation (an unsynchronized shock) as soon as a defibrillator arrives, with high-quality CPR performed continuously before and immediately after each shock. Early defibrillation is the single intervention most associated with survival in VF/pulseless VT. Amiodarone is an antiarrhythmic used in refractory VF/pulseless VT, but it is given after shocks and CPR are underway, not first — defibrillation and compressions take precedence. Synchronized cardioversion is used for organized rhythms in a client who still has a pulse (for example, unstable atrial fibrillation or SVT); it cannot even synchronize to the chaotic VF waveform and would be inappropriate here. Atropine treats symptomatic bradycardia and has no role in VF; it is not part of the pulseless arrest algorithm. Clinical pearl: contrast the shockable rhythms (VF, pulseless VT → defibrillate + CPR) with the non-shockable rhythms (asystole and PEA → CPR + epinephrine every 3-5 minutes, and never defibrillate). 'Shock the quiver, not the flat line.' The pillars of survival are early high-quality CPR and early defibrillation, minimizing interruptions to compressions.
Question 9 · Beta-blocker (metoprolol) administration
Before administering the morning dose of metoprolol, the nurse completes an assessment. Which finding indicates the nurse should hold the dose and notify the provider?
- A Apical heart rate of 52 beats per minute
- B Client reports a mild tension headache
- C Respiratory rate of 18 breaths per minute
- D Blood pressure of 138/84 mm Hg
Show answer & rationale
Correct answer: A
Beta-blockers such as metoprolol lower heart rate, blood pressure, and myocardial contractility. Before administration the nurse should assess the apical pulse for a full minute and the blood pressure, and hold the dose for a heart rate below 60 beats per minute or a systolic blood pressure below the ordered parameter, notifying the provider. An apical rate of 52 is below 60 and warrants holding the dose to avoid worsening bradycardia and reduced cardiac output. A blood pressure of 138/84 mm Hg does not meet hold criteria — it is not hypotensive and giving the dose is appropriate. A mild tension headache is not a reason to hold a beta-blocker; it is unrelated to the drug's hemodynamic effects. A respiratory rate of 18 is within the normal adult range (12-20) and is not a hold parameter for metoprolol (though the nurse remains alert for bronchospasm in clients with reactive airway disease). Clinical pearl: assess the apical (not radial) pulse for beta-blockers and digoxin, and never stop a beta-blocker abruptly — sudden withdrawal causes rebound tachycardia, hypertension, and can precipitate angina, MI, or dysrhythmias. Doses should be tapered under provider guidance.
Question 10 · Post cardiac catheterization / PCI care
A client returns to the unit after a percutaneous coronary intervention (PCI) performed through the right femoral artery. Which nursing actions are appropriate? Select all that apply.
- A Raise the head of the bed to 90 degrees right away for comfort
- B Inspect the femoral insertion site for bleeding or hematoma formation
- C Encourage oral fluids and monitor urine output and renal function
- D Assess the right dorsalis pedis and posterior tibial pulses frequently
- E Keep the affected leg straight and maintain bed rest per protocol
- F Ambulate the client in the hallway immediately to prevent clot formation
Show answer & rationale
Correct answer: B, C, D, E
After a femoral PCI, the nurse must confirm perfusion distal to the puncture site by assessing the dorsalis pedis and posterior tibial pulses (and checking color, temperature, and capillary refill) frequently, comparing them to baseline and the opposite limb — a diminished or absent pulse can signal arterial occlusion or thrombus. Inspecting the insertion site for bleeding or hematoma is essential because the femoral artery is a high-pressure vessel and the client is anticoagulated, making hemorrhage the major early complication. Keeping the affected extremity straight and maintaining bed rest per protocol prevents flexion at the hip that could dislodge the closure/clot and trigger bleeding. Encouraging fluids and monitoring urine output and renal function helps flush the iodinated contrast dye and detect contrast-associated acute kidney injury (CA-AKI). Ambulating the client immediately is incorrect and dangerous — early hip flexion and standing greatly increase the risk of arterial bleeding and hematoma; ambulation is delayed until the ordered bed-rest period is complete. Raising the head of the bed to 90 degrees right away is also incorrect because it flexes the hip and the groin site; the head of the bed is usually kept low (typically no more than 30 degrees) per protocol. Clinical pearl: for femoral access, remember to keep the leg straight, the site flat, and the pulses checked — 'flat, straight, and pulses.'
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Cardiac NCLEX FAQ
Is the old MONA sequence (morphine, oxygen, nitroglycerin, aspirin) still correct for chest pain on the NCLEX?
No — MONA is outdated as a routine order of care. Current AHA/ACC practice is to obtain a 12-lead ECG within 10 minutes, give chewable aspirin, and give nitroglycerin only if the client is not hypotensive (hold for SBP below 90 mm Hg) and has not taken a PDE5 inhibitor. Oxygen is given only when SpO2 is below 90% or the client is hypoxic/dyspneic, not to everyone. Morphine is no longer first-line and is reserved for pain not relieved by nitrates. On the NCLEX, prioritize the ECG and aspirin, and be cautious with routine oxygen and morphine.
How do I quickly tell left-sided from right-sided heart failure?
Use the memory aid Left = Lungs, Right = Rest of the body. Left-sided failure backs up into the pulmonary circulation, so you see respiratory signs: crackles, dyspnea, orthopnea, and paroxysmal nocturnal dyspnea. Right-sided failure backs up into the systemic circulation, so you see peripheral/systemic signs: jugular venous distention, dependent and peripheral edema, hepatomegaly, and ascites. They often coexist because left-sided failure is the most common cause of right-sided failure. Regardless of type, daily morning weights are the most reliable early indicator of fluid retention.
Which cardiac arrest rhythms get defibrillated, and which do not?
Defibrillate the shockable rhythms: ventricular fibrillation and pulseless ventricular tachycardia. For these, the priority is immediate defibrillation (an unsynchronized shock) plus high-quality CPR. Do NOT defibrillate the non-shockable rhythms — asystole and pulseless electrical activity (PEA). For those, the treatment is high-quality CPR plus epinephrine every 3-5 minutes and searching for reversible causes. A quick reminder: 'shock the quiver, not the flat line.' Synchronized cardioversion is different — it is used for organized, unstable rhythms in a client who still has a pulse, such as unstable atrial fibrillation or SVT.
What should I always check before giving a beta-blocker like metoprolol?
Assess the apical pulse for a full minute and check the blood pressure. Hold the dose and notify the provider if the heart rate is below 60 beats per minute or the systolic blood pressure is below the ordered parameter, because beta-blockers slow the heart and lower blood pressure. Just as important: never stop a beta-blocker abruptly. Sudden withdrawal causes rebound tachycardia and hypertension and can trigger angina, myocardial infarction, or dysrhythmias. Any discontinuation should be a gradual taper under provider guidance.